Military Retirement Pay Calculator

Military retirement pay: what this calculator estimates

This calculator provides an estimate of monthly and annual retired pay for active-duty members under two major systems:

• Legacy “High-36” (typically for members who entered service before 1/1/2018 and did not opt in to BRS)
• Blended Retirement System (BRS) (typically for members who entered on/after 1/1/2018 or who opted in)

It is designed to help you compare the pension portion (the defined benefit) and, for BRS, a simple modeled retirement-income add-on based on your estimated TSP balance. Results are for planning and education only; your actual retired pay is determined by law and DFAS/your service.

Inputs: how to choose good numbers

Years of service

For an active-duty regular retirement, members generally need 20 years of creditable service to receive an immediate pension. This calculator assumes you are eligible once you enter 20+ years.

Monthly Base Pay (Current $) vs. “High-36”

The statutory formula uses High-36: the average of your highest 36 months of basic pay (not including BAH/BAS or most special pays). The form asks for “current monthly base pay” because many users don’t have their full High-36 history handy.

Important: This calculator treats the value you enter for monthly base pay as a proxy for your High-36 average. If you were recently promoted, your true High-36 average may be lower than your current pay; if you have been stable in grade for several years, it may be closer.

Estimated TSP balance (BRS)

BRS includes government TSP contributions and matching (if you contribute). TSP outcomes depend on contribution rate, fund choices, market returns, and fees. To keep the calculator simple, the comparison models TSP as an account balance at retirement and converts it into an estimated monthly income stream using a withdrawal-rate assumption (explained below).

Formulas used

Let:

• Y = years of service at retirement
• H = High-36 average monthly basic pay (approximated by the “monthly base pay” input)

Legacy (High-36) pension

Legacy retired pay multiplier is 2.5% per year of service:

BRS pension

BRS uses a reduced multiplier of 2.0% per year of service:

Monthly Pension = H × 0.02 × Y

Simple modeled TSP “monthly income” (BRS)

To compare pension-only Legacy to BRS (pension + investments), the calculator estimates a monthly withdrawal from TSP using an annual withdrawal rate of 4% (a common planning heuristic). Converted to a monthly figure:

Estimated Monthly TSP Withdrawal = (TSP Balance × 0.04) ÷ 12

This is equivalent to:

Estimated Monthly TSP Withdrawal ≈ TSP Balance ÷ 300

Total Estimated Monthly (BRS) = (BRS Monthly Pension) + (Estimated Monthly TSP Withdrawal)

Interpreting your results

• Monthly pension (Legacy or BRS) is the defined-benefit portion tied to High-36 and years served. It is not dependent on market returns.
• BRS “total monthly” shown by the calculator is an illustrative combination of pension + a modeled TSP withdrawal. That TSP portion is not guaranteed and will vary with investment performance and your withdrawal strategy.
• If you want an apples-to-apples comparison, focus first on pension vs. pension, then separately evaluate whether your contributions + matching could plausibly build the TSP balance you enter.

Worked example

Assume:

• Years of service (Y): 22
• High-36 proxy monthly pay (H): $6,000
• Estimated TSP at retirement (BRS): $400,000

Legacy

Monthly Pension = 6,000 × 0.025 × 22 = $3,300

Annual Pension = 3,300 × 12 = $39,600

BRS

Monthly Pension = 6,000 × 0.02 × 22 = $2,640

Estimated Monthly TSP Withdrawal ≈ 400,000 ÷ 300 = $1,333

Total Estimated Monthly = 2,640 + 1,333 = $3,973

Total Estimated Annual (Year 1) = 3,973 × 12 = $47,676

Legacy vs. BRS comparison (high-level)

Assumptions & limitations (read before relying on the estimate)

• High-36 approximation: The calculator uses your entered “current monthly base pay” as a stand-in for High-36. This can over/under-estimate pension if your pay changed significantly in the last 36 months.
• Taxes not included: Results are gross estimates and do not account for federal/state taxes, withholding, or tax-advantaged treatment of some benefits.
• Allowances and special pays excluded: Military retired pay is based on basic pay (with specific rules). BAH/BAS are not included in basic pay.
• COLA/inflation not modeled: The calculator does not apply annual cost-of-living adjustments or inflation-adjusted purchasing power.
• Survivor Benefit Plan (SBP) not modeled: SBP premiums reduce retired pay if elected.
• VA disability interactions not modeled: VA disability compensation, offsets, CRDP/CRSC eligibility, and their impact on net income are not included and can materially change outcomes.
• Reserve/National Guard retirement not supported: This estimate is oriented to active-duty (regular) retirement timing and rules; reserve component retirement uses points and different start ages.
• TSP withdrawal assumption: The “TSP ÷ 300” conversion assumes a 4% annual withdrawal rate. This is a planning heuristic, not a guarantee, and may be too high or too low depending on market conditions, retirement horizon, and asset allocation.
• BRS continuation pay / lump-sum options: This calculator does not attempt to model continuation pay, lump-sum elections, or reduction factors. Those features have eligibility rules and trade-offs that require individualized review.

Suggested sources for verification

For official definitions and current policy details, review DFAS and DoD retirement/BRS resources and your service’s retirement guidance. If you are close to retirement, consider validating High-36 and creditable service with official statements and a retirement services officer.